WO2004043891A1 - Catalytic method for the production of carbonyl compounds - Google Patents

Abstract

The invention relates to a catalytic method for the production of aliphatic and aromatic carbonyl compounds with at least one aldehyde or ketone function, whereby said compounds can also comprise at least one aldehyde and ketone function. A starting material comprising at least one aliphatic- and/or aromatic-bonded functional group of formula (I), where R<1> = H, alkyl or aryl, X = H, or a group which may be substituted by the sulphinyl group of a sulphoxide during the catalytic reaction, n= a whole number from 1 to 8, is oxidised in the presence of a sulphoxide and/or a sulphide and the presence of iron salts or redox pairs of iron/copper or silver/copper salts, by means of an oxidising agent with a redox potential of Eo > + 2 V vs. NHE, whereby the sulphoxide or sulphide has a catalytic function. The method permits the production of carbonyl compounds, in particular, (poly)aldehydes and (poly)ketones with high selectivity, whereby the formation of alcohols and carboxylic acids, dimerisation products and other by-products is reduced to a minimum or essentially prevented. The final products obtained find application as important intermediates and final products.

Description

 Catalytic process for the production of carbonyl compounds

The present invention relates to a catalytic process for the preparation of aliphatic and aromatic carbonyl compounds with at least one aldehyde or. Ketone function, whereby these compounds can also have aldehyde and ketone functions simultaneously.

The above class of compounds includes notable products which are generally important intermediates or end products in various fields of the secondary and fine chemical industries.

Due to the importance of the products mentioned, many processes have already been proposed for their production. In some of these processes, alkyl or hydroxyalkyl compounds are used as starting materials.

In any case, however, the previously known methods are not generally applicable or are too complicated and expensive for industrial use. Above all, they show insufficient selectivity when it comes to producing polyaldehydes or polyketones, i.e. Products that have multiple aldehyde or ketone functions in the same molecule.

If you use the previously known direct oxidation processes, such as described in patents DE 2605678, CH 609318 or DE 2944477, then mixed-oxidized products are formed in which both carboxyl, hydroxyalkyl and formyl or ketone groups are combined on the same molecule.

For example, the selectivity in the production of 4,4'-oxybis (benzaldehyde) from 4,4'-oxybis (toluene) by the previously known direct oxidation processes is in the best case 30-40 mol%.

It is also known that compounds with functional groups of the formula I

R ¹ (I)

where R ^{1 is} hydrogen, alkyl or aryl, X is halogen and n = 1,

^RY o ³— - - or«- ^RS-^R3 ₊ H_X T ^{x RI}

^R Y o ³ - - - or «- ^R S- ^R3 ₊ H _X

react with sulfoxides in which R ² and R ^{3 are} alkyl or aryl to form aldehyde or ketone groups and sulfides according to reaction (1) [Kornblum et al., J. Am. Chem. Soc, 1959, 81, 4113].

In an analogous manner, functional groups of the formula I in which X is hydroxyl can also be converted with sulfoxides into aldehyde or ketone groups and sulfides if the hydroxyl group reacts with a previously derivatized sulfoxide, e.g. derivatized with acid chlorides [Omura et al., Tetrahedron 1978, 34, 1651; Mancuso et al., Synthesis, 1981, 165], dicyclohexylcarbodiimide [Pfitzner et al., J. Am. Chem. Soc, 1965, 87, 5661] or acid anhydrides [Albright et al., J. Am. Chem. Soc. 1967, 89, 2416].

Finally, it has recently become known that functional groups of the formula I, in which R ^{1 is} alkyl or aryl and X are hydrogen, react with sulfoxides and, in the presence of polyoxomolybdate, also according to reaction (1) to form ketones and sulfides [Khenkin et al., J . At the. Chem. Soc, 2002, 124, 4198]. In all of these cases, which are described by reaction (1), the stoichiometric amount of the corresponding sulfides arises from sulfoxides.

The object of the present invention is to produce aliphatic and aromatic carbonyl compounds with high selectivity in a catalytic process.

The object is achieved by a catalytic process according to claim 1, in that the sulfide formed is continuously oxidized back to the corresponding sulfoxide by adding a suitable oxidizing agent, so that the sulfoxide or the sulfide only has to be used as a catalyst. The procedure is described below.

The starting material for this catalytic process is a compound which has at least one (n> 1) functional group of the formula I,

R (l)

R (l)

wherein R ^{1 is} hydrogen, alkyl or aryl, X is hydrogen or a group which can be substituted for the sulfinyl group of a sulfoxide during the catalytic reaction and n is an integer value between 1 and 8. This compound is in the presence of a sulfoxide and / or a sulfide in the presence of iron salts or redox pairs such as Fe / Cu or Ag / Cu salts by means of an oxidizing agent with a redox potential of E ₀ > + 2 V vs. NHE (normal hydrogen electrode), preferably oxidized using a persulfate salt. The presence of the sulfoxide and / or a sulfide first makes it possible to produce the desired carbonyl compounds with very high selectivity, the formation of alcohols, carboxylic acids, dimerization products and other secondary by-products being decisively reduced or essentially prevented.

This surprising appearance of the process according to the invention is attributable to the intermediate formation of functional groups of the formula II,

wherein R ^{1 is} hydrogen, alkyl or aryl, R ² and R ^{3 are} alkyl or aryl, n are integer values between 1 and 8. Dialkyl, alkylaryl or diaryl sulfoxides and mixtures thereof are used as sulfoxides. Dialkyl, alkylaryl or diaryl sulfides and mixtures thereof are used as sulfides. The sulfoxides serve as oxygen transfer catalysts, which are either soluble in the reaction solution or on an im Slurry solids are immobilized. The sulfides are either soluble in the reaction solution or immobilized on a solid suspended in the reaction mixture.

The mole fraction of the sulfoxide and / or sulfide is 1-90 mol% based on the aldehyde or ketone function formed. In addition, a molar fraction of the sulfoxide and / or the sulfide of 1 - 500 mol% can also be used if, for example, which require kinetic reaction conditions. In this case too, the reoxidation of the intermediate sulfide is of major importance.

The presence of a sulfoxide and / or a sulfide in the reaction mixture can take place in various ways.

The sulfoxide or sulfide can be alone or in a mixture of sulfoxides or sulfides. In addition to the sulfide, the sulfoxide can also be present individually or in a mixture.

Surprisingly, the use of at least one sulfoxide and / or at least one sulfide in the reaction mixture leads to high selectivity. Iron salts alone or in combination with silver salts serve primarily to cleave the persulfate to the actual oxidizing agent, the sulfate radical anion. The use of a copper salt together with an iron or silver salt proves to be advantageous in the selective production of carbonyl compounds. For example, the formation of dimerization products is effectively suppressed.

The process described can be carried out by gradually adding the persulfate in the form of powder or in an aqueous solution with vigorous stirring to the starting material which is dissolved in an inert organic solvent, in water or in a mixture thereof. The sulfoxide and / or the sulfide can be dissolved or slurried in this reaction mixture.

The most comprehensive conditions which give the best selectivity with regard to the starting material are the addition of a sulfoxide and / or a sulfide and the gradual addition of an aqueous solution of persulfate with vigorous stirring to a mixture of the starting material dissolved in water with a proportion of organic , water-miscible solvent. Particularly suitable solvents are Acetonitrile, methyl and ethyl alcohol, acetone, acetic acid, dimethylformamide, acetamide.

The proportion of organic solvent in a mixture with water is preferably 25-75%, based on the water.

Effective metal salts are for example:

a) All water-soluble iron salts, preferably sulfates, nitrates and acetates; b) all water-soluble silver salts, in particular sulfates, nitrates and acetates; c) all water-soluble copper salts, preferably sulfates, nitrates and acetates.

As a rule, the concentration of the iron or silver salt is 0.005 - 10 mol% based on the starting material to be oxidized. The copper salt is preferably used in the redox pairs in a molar ratio of Fe: Cu or Ag: Cu of 0.1-3.

As a rule, the oxidation is carried out at a temperature of 10 - 100 ° C.

According to the invention, the process can also be based on a mixture of starting materials, a similarly high selectivity for carbonyl compounds being achieved.

With the catalytic oxidation process according to the invention, the selectivity of the carbonyl compounds produced can be increased considerably, in some cases to over 90%, under optimized reaction conditions.

The examples below explain the present invention in detail without claiming to have fully described the technical potential according to the invention, in particular the examples have not been optimized in any way.

Example 1: Preparation of 4,4'-oxybis (benzaldehyde)

In a 100 ml reactor gassed with argon, 2 g of 4,4'-oxybis (toluene) are (CAS Reg. No. 1579-40-4) [10 mmol] dissolved in 39.2 ml acetonitrile with the addition of 0.8 ml dimethyl sulfoxide [11.2 mmol] at 75 ° C. 60 mg Cu (OAc) ₂ , 30 mg FeS0 ₄ -7 H ₂ 0 and 10 ml water are added to the solution. 10.8 g of Na ₂ S ₂ 0 ₈ dissolved in 30 ml of water are then added dropwise with vigorous stirring. The reaction is complete after 45 minutes. The organic phase is extracted exhaustively with ethyl acetate. The products formed are examined using HPLC. The yield of the dialdehyde 4,4'-oxybis (benzaldehyde) (CAS Reg. No. 2215-76-1) is 87 mol%. This yield is thus significantly higher than the yields with previously known oxidation processes of 30-40%, whereby the selectivity of the process according to the invention is distinguished.

Example 2: Preparation of 4,4 '- (1-methylethane-1,1-diyl) bis (benzaldehyde)

2.24 g of 1,1 '- (1-methylethane-1,1-diyl) -bis (4-methylbenzene) (CAS Reg. No. 1823-31-0) [10 mmol] in 39.2 ml of acetonitrile with the addition of 0.8 ml of dimethyl sulfoxide [11.2 mmol] at 75 ° C. 60 mg Cu (OAc) ₂ and 30 mg FeS0 ₄ -7 H ₂ 0 and 10 ml water were added to the solution.

10.8 g of Na ^ O _g dissolved in 30 ml of water were then added dropwise with vigorous stirring. The reaction is complete after 100 minutes. The organic phase is with

Extracted ethyl acetate exhaustively.

The yield of the dialdehyde 4,4 '- (1-methylethane-1,1-diyl) -bis (benzaldehyde) (CAS Reg.

No. 46948-52-1) is 86% HPLC.

Example 3: Preparation of biphenyl-4,4'-dicarbaldehyde

In a 100 ml reactor gassed with argon, 1.82 g of 4,4'-dimethyl-biphenyI

(CAS Reg. No. 613-33-2) [10 mmol] in 39.2 ml acetonitrile with the addition of 0.8 ml

Dimethyl sulfoxide [11.2 mmol] dissolved at 70 ° C. 60 mg of Cu (OAc) ₂ and

50 mg FeS0 ₄ -7 H ₂ 0 and 10 ml water added. 11.8 g Na ₂ S ₂ 0 ₈ dissolved in 30 ml

Water was then added dropwise with vigorous stirring. The reaction is complete after 250 minutes. The organic phase is extracted exhaustively with ethyl acetate.

The yield of the dialdehyde biphenyl-4,4'-dicarbaldehyde (CAS Reg. No. 66-98-8) is 85 mol%. Example 4: Preparation of 4-methoxy-benzaldehyde

2.44 g of 1-methoxy-4-methylbenzene (CAS Reg. No. 104-93-8) [20 mmol] in 39 ml of acetonitrile with the addition of 1.0 ml of dimethyl sulfoxide [14.1 mmol] were placed in a 100 ml reactor gassed with argon. solved at 70 ° C. 65 mg Cu (OAc) ₂ and 30 mg FeS0 ₄ -7 H ₂ 0 and 10 ml water were added to the solution. 11.0 g Na ₂ S ₂ 0 ₈ dissolved in 30 ml

Water was then added dropwise with vigorous stirring. The reaction is complete after 120 minutes.

The yield of the monoaldehyde 4-methoxy-benzaldehyde (CAS Reg. No. 123-11 -5) is 92 mol%.

Example 5: Preparation of 4,4'-oxybis (benzaldehyde)

gelöst in 30 ml Wasser werden anschliessend unter heftigem Rühren zugetropft. Nach 65 Minuten ist die Reaktion beendet. Die organische Phase wird mit Ethylacetat erschöpfend extrahiert. Die Ausbeute des Dialdehyds 4,4'-Oxybis(benzaldehyd) (CAS Reg. Nr. 2215-76-1 ) beträgt 84 mol%.In a 100 ml reactor gassed with argon, 2 g of 4,4'-oxybis (toluene) (CAS Reg. No. 1579-40-4) [10 mmol] in 39.2 ml of acetonitrile with the addition of 0.9 ml of dimethyl sulfide [11.0 mmol]. dissolved at 75 ° C. 60 mg Cu (OAc) ₂ , 30 mg FeS0 ₄ -7 H ₂ 0 and 10 ml water are added to the solution. 16.2 g

dissolved in 30 ml of water are then added dropwise with vigorous stirring. The reaction is complete after 65 minutes. The organic phase is extracted exhaustively with ethyl acetate. The yield of the dialdehyde 4,4'-oxybis (benzaldehyde) (CAS Reg. No. 2215-76-1) is 84 mol%.

Example 6: Preparation of 4,4'-oxybis (benzaldehyde)

In a 100 ml reactor gassed with argon, 2 g of 4,4'-oxybis (toluene) are

(CAS Reg. No. 1579-40-4) [10 mmol] in 39.2 ml acetonitrile with the addition of 1.5 ml

Methylphenyl sulfoxide [11.0 mmol] dissolved at 75 ° C. 60 mg become the solution

Cu (OAc) ₂ , 30 mg FeS0 ₄ -7 H ₂ 0 and 10 ml water added. 16.2 g of Na ₂ S ₂ 0 ₈ dissolved in 30 ml of water are then added dropwise with vigorous stirring. After 45

Minutes the reaction is complete. The organic phase is extracted exhaustively with ethyl acetate.

The yield of the dialdehyde 4,4'-oxybis (benzaldehyde) (CAS Reg. No. 2215-76-1) is 84 mol%.

Claims

claims 1. A process for the preparation of aliphatic and aromatic carbonyl compounds with at least one aldehyde or ketone function, wherein these compounds can also have at least one aldehyde and ketone function, characterized in that at least one starting material having at least one aliphatic and / or aromatically bound functional group of the formula I.

R ¹ (I) in which R ^{1 is} hydrogen, alkyl or aryl, X is hydrogen or a group which can be substituted for the sulfinyl group of a sulfoxide during the catalytic reaction, n is an integer value between 1 and 8, in the presence of at least one sulfoxide and / or at least one sulfide in the simultaneous presence of iron salts or redox pairs of iron / copper or silver / copper salts using at least one oxidizing agent with a redox potential of E ₀ > + 2 V vs. NHE, is oxidized, the sulfoxide and / or the sulfide being used in a catalytic function. 2. The method according to claim 1, characterized in that for the production of aliphatic and aromatic mono- and polyaldehydes at least one starting material is oxidized, which has at least one aliphatic and / or aromatically bound functional group of formula I, wherein R ^{1 is} hydrogen. 3. The method according to claim 1, characterized in that for the production of aliphatic and aromatic mono- and polyketones at least one starting material is oxidized, which has at least one aliphatic and / or aromatically bound functional group of formula I, wherein R ^{1 is} alkyl or aryl , 4. The method according to claim 1, characterized in that for the production of carbonyl compounds which have both aliphatically or aromatically bound aldehyde and aliphatically or aromatically bound ketone functions, at least one starting material is oxidized, the at least one aliphatic and / or aromatically bound Functional group of formula I, wherein R ^{1 is} hydrogen in the formation of aldehyde functions and alkyl or aryl in the formation of ketone functions. 5. The method according to any one of claims 1-4, characterized in that dialkyl, diaryl or alkylaryl sulfoxides are used as sulfoxides and that dialkyl, diaryl or alkylaryl sulfides are used as sulfides. 6. The method according to any one of claims 1-5, characterized in that at least one sulfoxide and / or at least one sulfide is used in the reaction mixture. 7. The method according to any one of claims 1-6, characterized in that the at least one sulfoxide and / or the at least one sulfide is dissolved in the reaction mixture. 8. The method according to any one of claims 1-6, characterized in that the at least one sulfoxide and / or the at least one sulfide is immobilized on a solid and this is slurried in the reaction mixture. 9. The method according to any one of claims 1-8, characterized in that the at least one sulfoxide and / or the at least one sulfide is used with a proportion of 1 - 90 mol% based on the aldehyde or ketone function formed. 10. The method according to any one of claims 1-8, characterized in that the at least one sulfoxide and / or the at least one sulfide is used with a proportion of 1 - 500 mol% based on the aldehyde or ketone function formed. 11. The method according to any one of claims 1-10, characterized in that the oxidizing agent is used in the form of powder or in an aqueous solution. 12. The method according to any one of claims 1-11, characterized in that persulfate salts or a mixture thereof is used as the oxidizing agent. 13. The method according to claim 12, characterized in that alkali metal or ammonium persulfate are used as persulfate salts. 14. The method according to any one of claims 1-13, characterized in that water-soluble iron salts, preferably from the group of sulfates, nitrates and acetates, are used alone or in a mixture with water-soluble copper salts. 15. The method according to any one of claims 1-13, characterized in that water-soluble silver salts, preferably from the group of sulfates, nitrates and acetates, are used alone or in a mixture with water-soluble copper salts. 16. The method according to any one of claims 1-13, characterized in that water-soluble copper salts, preferably from the group of sulfates, nitrates and acetates, are used alone or in a mixture with iron or silver salts. 17. The method according to any one of claims 1-16, characterized in that iron or silver salts in the redox pairs are used in concentrations of 0.005 - 10 mol% based on the starting material to be oxidized and that the copper salt in a molar ratio of Fe: Cu or Ag: Cu from 0.1 - 3 is used. 18. The method according to any one of claims 1-17, characterized in that the oxidation is carried out in an inert reaction medium from the group water, organic solvent and a mixture thereof. 19. The method according to claim 18, characterized in that as the organic solvent acetonitrile, methyl and ethyl alcohol, acetone, acetic acid, dimethylform amide or acetamide is used. 20. The method according to any one of claims 1-19, characterized in that the oxidation is carried out at a temperature of 10 - 100 ° C.